More steps towards multiple global object support. Primitive cells
like strings, bigints, etc, don't actually have any connection to
the global object. Use the explicit API to clarify this.
btoa() takes a byte string, so it must decode the UTF-8 argument into
a Vector<u8> before calling encode_base64.
Likewise, in atob() decode_base64 returns a byte string, so that needs
to be converted to UTF-8.
With this, `btoa(String.fromCharCode(255))` is '/w==' as it should
be, and `atob(btoa(String.fromCharCode(255))) == String.fromCharCode(255)`
remains true.
It's broken for strings with characters outside 7-bit ASCII, but
it's broken in the same way as several existing functions (e.g.
charAt()), so that's probably ok for now.
Finally use Symbol.iterator protocol in language features :) currently
only used in for-of loops and spread expressions, but will have more
uses later (Maps, Sets, Array.from, etc).
Not only is this a much nicer api (can't pass a typo'd string into the
get_well_known_symbol function), it is also a bit more performant since
there are no hashmap lookups.
With the addition of symbol keys, work can now be done on starting to
implement the well-known symbol functionality. The most important of
these well-known symbols is by far Symbol.iterator.
This patch adds IteratorPrototype, as well as ArrayIterator and
ArrayIteratorPrototype. In the future, sometime after StringIterator has
also been added, this will allow us to use Symbol.iterator directly in
for..of loops, enabling the use of custom iterator objects. Also makes
adding iterator support to native objects much easier (as will have to
be done for Map and Set, when they get added).
This commit also exposes JSONObject's implementation of stringify to the
public, so that it can be used by test-js without having to go through
the interpreter's environment.
literal methods; add EnvrionmentRecord fields and methods to
LexicalEnvironment
Adding EnvrionmentRecord's fields and methods lets us throw an exception
when |this| is not initialized, which occurs when the super constructor
in a derived class has not yet been called, or when |this| has already
been initialized (the super constructor was already called).
This is a helper function based on the getter/setter definition logic from
ObjectExpression::execute() to look up an Accessor property if it already
exists, define a new Accessor property if it doesn't exist, and set the getter or
setter function on the Accessor.
Divide the Object constructor into three variants:
- The regular one (takes an Object& prototype)
- One for use by GlobalObject
- One for use by objects without a prototype (e.g ObjectPrototype)
Instead of taking the JS::Heap&. This allows us to get rid of some
calls to JS::Interpreter::global_object(). We're getting closer and
closer to multiple global objects. :^)
We're still missing optional argument support, so this implementation
doesn't support fill(), only fill(fill_rule).
Still it's really nice to get rid of so much hand-written wrapper code.
To allow implementing the DOM class hierarchy in JS bindings, this
patch adds an inherits() function that can be used to ask an Object
if it inherits from a specific C++ class (by name).
The necessary overrides are baked into each Object subclass by the
new JS_OBJECT macro, which works similarly to C_OBJECT in LibCore.
Thanks to @Dexesttp for suggesting this approach. :^)
Instead of only checking the class_name(), we now generate an is_foo()
virtual in the wrapper generator. (It's currently something we override
on Bindings::Wrapper, which is not really scalable.)
Longer term we'll need to think up something smarter for verifying that
one wrapper "is" another type of wrapper.
Also let's settle on calling the operation of fetching the "this" value
from the Interpreter and converting it to a specific Object pointer
typed_this() since consistency is nice.
To make sure that everything is set up correctly in objects before we
start adding properties to them, we split cell allocation into 3 steps:
1. Allocate a cell of appropriate size from the Heap
2. Call the C++ constructor on the cell
3. Call initialize() on the constructed object
The job of initialize() is to define all the initial properties.
Doing it in a second pass guarantees that the Object has a valid Shape
and can find its own GlobalObject.
